Novel non-invasive perfusion monitor and system, specially configured oximeter probes, methods of using same, and covers for probes

• US 20030236452A1
• Filed: 06/20/2002
• Published: 12/25/2003
• Est. Priority Date: 06/20/2002
• Status: Active Grant

• Current Assignee: Beta Biomed Services, Inc., University of Florida Research Foundation, Incorporated (State University System of Florida)
• Original Assignee: Beta Biomed Services, Inc.
• Inventors: Nappo, Robert, Layon, A. Joseph, Melker, Richard, Worley, George
• Granted Patent: US 6,909,912 B2
• Time in Patent Office: Days
• US Class Current: 600/323
• CPC Class Codes: A61B 2560/0276 Determining malfunction
• CPC Class Codes: A61B 2562/247 Hygienic covers, i.e. for covering the sensor or apparatus during use
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/02427 Details of sensor
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/0295 using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
• CPC Class Codes: A61B 5/036 by means introduced into body tracts A61B5/032 and A61B5/035 take precedence
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/0836 Measuring rate of CO2 production
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: A61B 5/0873 using optical means
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61B 5/6819 Nose
• CPC Class Codes: A61B 5/682 Mouth, e.g., oral cavity; tongue; Lips; Teeth
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6829 Foot or ankle
• CPC Class Codes: A61B 5/7278 : Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61B 5/7282 : Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61M 16/0003 : Accessories therefor, e.g. sensors, vibrators, negative pressure
• CPC Class Codes: A61M 16/0051 : with alarm devices
• CPC Class Codes: A61M 16/0057 : Pumps therefor
• CPC Class Codes: A61M 16/021 : operated by electrical means A61M16/202 – A61M16/205 take precedence
• CPC Class Codes: A61M 16/0666 : Nasal cannulas or tubing devices for improving normal breathing through the nose A61F5/08; nose filters A62B23/06; outside holding devices A61M25/02
• CPC Class Codes: A61M 16/0672 : Nasal cannula assemblies for oxygen therapy
• CPC Class Codes: A61M 16/08 : Bellows; Connecting tubes having means for taking samples G01N1/22; Water traps; Patient circuits
• CPC Class Codes: A61M 16/085 : Gas sampling
• CPC Class Codes: A61M 16/20 : Valves specially adapted to medical respiratory devices
• CPC Class Codes: A61M 2202/0007 : introduced into the body
• CPC Class Codes: A61M 2202/0208 : Oxygen
• CPC Class Codes: A61M 2202/03 : Gases in liquid phase, e.g. cryogenic liquids
• CPC Class Codes: A61M 2205/3561 : local, e.g. within room or hospital
• CPC Class Codes: A61M 2205/3569 : sublocal, e.g. between console and disposable
• CPC Class Codes: A61M 2210/0618 : Nose
• CPC Class Codes: A61M 2210/0625 : Mouth
• CPC Class Codes: A61M 2210/0662 : Ears
• CPC Class Codes: A61M 2230/005 : Parameter used as control input for the apparatus
• CPC Class Codes: A61M 2230/06 : Heartbeat rate only
• CPC Class Codes: A61M 2230/205 : partial oxygen pressure (P-O2)
• CPC Class Codes: A61M 2230/30 : Blood pressure A61M2230/04 takes precedence
• CPC Class Codes: A61M 2230/42 : Rate
• CPC Class Codes: A61M 2230/432 : partial CO2 pressure (P-CO2)

Abstract

The present invention relates to a novel non-invasive perfusion/resistance status monitor system and methods of using the same, and more specifically, a vascular perfusion status monitor system receiving and processing signals from at least two pulse oximeter probes, where each of the at least two pulse oximeter probes are situated at advantageously different locations in a patient. Novel pulse oximeter probes are configured to be placed, respectively, across the lip or cheek, across the septum or nares of the nose, and on the tongue. These probes are fabricated to provide signals to estimate arterial oxygen saturation. Conventional oximeter probes also can be configured to function according to the novel methods of determining differences in peripheral blood flow and/or resistance described herein.

Claims

1. A pulse oximetry probe for use in the mouth cavity for measurement of pulse-based differences in light absorbence across the vascularized tissue of a lip or cheek of a patient, comprising:

a. a resilient probe frame having an inner face and an outer face, said frame comprising a proximal arm connecting at one end to a cable and at the other end to a bridging section of said frame, said bridging section connecting the proximal arm to one end of a distal arm of said frame, wherein a portion of said distal arm is at a determined distance from an opposing portion of said proximal arm;

b. a first pad comprising at least two light-generating structures that emit light at at least two different wavelength bands known to differentiate oxygenated from non-oxygenated hemoglobin, positioned on the inner face of said portion of the distal arm or of the proximal arm;

c. a second pad comprising at least one light-detecting structure that detects light transmitted from said first pad, positioned on the inner face of the arm opposing the first pad; and

d. first individual conductors for energizing said at least two light-generating structures, connecting said structures to a monitoring system for light signal production and modulation, and second individual conductors connecting said at least one light-detecting structure to said monitoring system to convey signals of light detected by said at least one light-detecting structure, said first and said second individual conductors passing within said resilient probe frame and thereafter through a cable for carrying said first and said second individual conductors to said monitoring system.

2. The pulse oximetry probe of claim 1, additionally comprising a boot to seal the junction between said probe frame and said cable.

3. The pulse oximetry probe of claim 2, wherein said first and second pads are dome-shaped and spaced apart sufficiently to comfortably engage both sides of the lip or cheek tissue of a patient.

4. The pulse oximetry probe of claim 2, wherein said probe frame is hook-shaped, and is sized to engage both sides of the lip or cheek tissue of an average pediatric patient comfortably between said first and second pads.

5. The pulse oximetry probe of claim 2, wherein said probe frame is hook-shaped, and is sized to engage both sides of the lip or cheek tissue of an average adult patient comfortably between said first and second pads.

6. A pulse oximetry probe to measure pulse-based differences in light absorbence by the vascularized tissue of the septum of the nose, comprising:

a. a housing from which emanates two substantially flattened extensions sufficiently sized and spaced to enter the nares of a nose and contact both sides of the septum;

b. at least two light-generating structures that emit light at at least two different wavelength bands, positioned on the inside face of one of the two substantially flattened extensions;

c. at least one light-detecting structure that detects light transmitted from said at least two light-generating structures, positioned on the inside face of the other of the two substantially flattened extensions; and

d. first individual conductors for energizing said at least two light-generating structures, connecting said structures to a monitoring system for light signal production and modulation, and second individual conductors connecting said at least one light-detecting structure to said monitoring system to convey signals of light detected by said at least one light-detecting structure, said first and said second individual conductors passing within said housing and thereafter through a cable for carrying said first and said second individual conductors to said monitoring system.

7. A pulse oximetry probe to measure pulse-based differences in light absorbence by the vascularized tissue of a tongue of a patient, comprising:

a. a first substantially flat arm which toward a first end has an extension for joining with a second substantially flat arm, and which toward a second end has a pad housing at least two light-generating structures that emit light at at least two different wavelength bands known to differentiate oxygenated from non-oxygenated hemoglobin;

b. said second substantially flat arm which toward a first end has an extension for joining with said first substantially flat arm, and which toward a second end has a pad at least one light-detecting structure that detects light transmitted from said first arm'"'"'s pad, positioned on the inner face of the arm opposing the first pad;

c. conductors leading from said at least two light-generating structures and said at least one light-detecting structure, and through a cable directed away from said probe;

d. means for hingedly joining said first substantially flat arm and said second substantially flat arm at said respective extensions; and

e. means for tensioning said first substantially flat arm and said second substantially flat arm around a section of the tongue of a patient.

8. A sleeve to cover parts of a pulse oximeter probe subject to exposure to bodily fluids or other contamination from a patient, said sleeve comprising:

a. a first section configured to slide over a first arm or extension of said pulse oximeter probe, wherein said first arm or extension bears a light-generating device; and

b. a second section configured to slide over a second arm or extension of said pulse oximeter probe wherein said second arm or extension bears a light-sensing device,

wherein said sleeve is composed of thin flexible material and permits light transmission at the areas covering said light-generating device and said light-sensing device.

9. A sleeve to cover parts of a pulse oximeter probe subject to exposure to bodily fluids or other contamination from a patient, said sleeve comprising:

a. a first section configured to slide over a first arm or extension of said pulse oximeter probe, wherein said first arm or extension bears a light-generating device;

b. a second section configured to slide over a second arm or extension of said pulse oximeter probe wherein said second arm or extension bears a light-sensing device; and

c. a joining section connecting said first and second sections, and further configured to cover components of said probe intervening between said first arm or extension and said second arm or extension,

wherein said sleeve is composed of thin flexible material and permits light transmission at the areas covering said light-generating device and said light-sensing device.

10. A sleeve to cover parts of a pulse oximeter probe subject to exposure to bodily fluids or other contamination from a patient, said sleeve comprising:

a. a first section configured to slide over a first arm or extension of said pulse oximeter probe and comprising a light-generating device and conductors thereof; and

b. a second section configured to slide over a second arm or extension of said pulse oximeter probe and comprising a light-sensing device and conductors thereof,

wherein said sleeve is composed of thin flexible material and is light transmission permissive at said light-generating device and said light-sensing device.

11. A sleeve to cover parts of a pulse oximeter probe subject to exposure to bodily fluids or other contamination from a patient, said sleeve comprising:

a. a first section configured to slide over a first arm or extension of said pulse oximeter probe and bearing a light-generating device and conductors thereof; and

b. a second section configured to slide over a second arm or extension of said pulse oximeter probe and bearing a light-sensing device and connectors thereof; and

c. a joining section connecting said first and second sections, and further configured to cover components of said probe intervening between said first arm or extension and said second arm or extension; and

d. wherein said sleeve is composed of thin flexible material and is light transmission permissive at said light-generating device and said light-sensing device.

12. A pulse oximetry probe for measurement of pulse-based differences in light absorbence across the vascularized tissue of a patient, comprising:

a. a first substantially flattened side, substantially longer than wide, having an inner face and an outer face, and bearing a hinging means connecting said first side to an opposing second side;

b. said second substantially flattened side, substantially longer than wide, having an inner face and an outer face, said second side connecting to said first side at said hinging means such that the inner faces of both sides substantially oppose each other and, based on the spacing and configuration of the hinging means, are sufficiently separable to widen to encompass said tissue an operative end;

c. at least two light-generating structures that emit light at at least two different wavelength bands known to differentiate oxygenated from non-oxygenated hemoglobin, positioned at the operative end on the inner face of said first side or said second side;

d. at least one light-detecting structure that detects light transmitted from said at least two light-generating structures, positioned at the operative end on the inner face of the side opposing said at least two light-generating structures; and

first individual conductors for energizing said at least two light-generating structures, connecting said structures to a monitoring system for light signal production and modulation, and second individual conductors connecting said at least one light-detecting structure to said monitoring system to convey signals of light detected by said at least one light-detecting structure, said first and said second individual conductors passing from said probe to said monitoring system.

13. The probe of claim 12, additionally comprising a first pad to enclose said at least two light-generating structures, and a second pad to enclose said at least one light-detecting structure.

14. A method for analyzing pulse oximeter probe signals from at least two sites on a living vertebrate to determine the presence or absence of, or to monitor changes in, impaired peripheral perfusion, comprising the steps of:

a. removably affixing a first pulse oximeter probe to a central source site located in the head of a patient in need of said method;

b. removably affixing a second pulse oximeter probe to a first peripheral site of interest on said patient;

c. measuring signals from said central source site pulse oximeter and said first peripheral site pulse oximeter;

d. averaging sufficient sequential signals from each site to obtain a statistically reliable average, and from said average calculating a time-set estimate of the arterial blood oxygen saturation, and repeating this averaging to obtain sequential time-set estimates from each site;

e. comparing a time-set estimate of the arterial blood oxygen saturation from the central source site with an estimate, taken at a similar time, of the arterial blood oxygen saturation from the first peripheral site; and

f. determining the presence or absence of, or the time-based changes in, impaired peripheral perfusion proximal to said first peripheral site.

15. The method of claim 14 wherein said central source site is selected from the group consisting of cheek, nasal septum, alar nares, and tongue.

16. The method of claim 14 wherein said first peripheral site is selected from the group consisting of a finger, a toe, and a section of tissue distal from an area of potential damage or disease adversely affecting, suspected or known to have compromised the peripheral vascular resistance and/or peripheral blood perfusion, and/or peripheral vascular disease.

17. The method of claim 14 wherein said monitoring assesses changes over time in oxygenation of tissues proximal to said second pulse oximeter during drug dosing/effectiveness and/or reoxygenation procedures.

18. The method of claim 14, additionally comprising estimating the blood pressure of said living vertebrate through analysis of pulse time delay between said at least two sites.

19. The method of claim 18, additionally comprising comparing the signals of said pulse time delay with blood pressure estimates obtained by other means, and applying a factor to enhance the accuracy of said estimating the blood pressure.

20. Apparatus for analyzing pulse oximeter probe signals from at least two sites on a living vertebrate, to determine the presence or absence of, or to monitor changes in, impaired peripheral perfusion, comprising:

a. means for receiving pulse oximeter probe signals from at least two sites on a living vertebrate, wherein at least one said site is a central source site and at least one said site is a peripheral site;

b. means for signal averaging sufficient signals from each pulse oximeter probe site to obtain a statistically reliable average;

c. means for calculating a time-set estimate of the arterial blood oxygen saturation based on said statistically reliable average;

d. repeating steps b and c to obtain sequential time-set estimates of arterial blood oxygen saturation from each site;

e. means for comparing a time-set estimate of the arterial blood oxygen saturation from the central source site with an estimate, taken at a similar time, of the arterial blood oxygen saturation from the first peripheral site;

f. means for determining the presence or absence of, or the time-based changes in, impaired peripheral perfusion proximal to said first peripheral site based on the extent to which said first peripheral site has lower oxygen saturation than said central source site; and

g. means for presenting results to a user of said apparatus.

21. The apparatus of claim 20, additionally comprising means for estimating blood pressure through analysis of pulse time delay between said at least two sites.

22. An oximeter monitor system for analyzing pulse oximeter probe signals from at least two sites on a living vertebrate, to determine the presence or absence of, or to monitor changes in, impaired peripheral perfusion, comprising:

a. output circuitry to deliver timed signals to energize light generating components of at least two pulse oximeter probes;

b. input circuitry to receive signals from said at least two pulse oximeter probes positioned at at least two sites on a living vertebrate, wherein at least one said site is a central source site and at least one said site is a peripheral site;

c. a computer loaded with software to

1. provide timed signals to energize said light generating components;

2. average sufficient signals from each pulse oximeter probe site to obtain a statistically reliable average;

3. calculate a time-set estimate of the arterial blood oxygen saturation based on said statistically reliable average;

4. repeat steps 2 and 3 to obtain sequential time-set estimates of arterial blood oxygen saturation from each site;

5. compare a time-set estimate of the arterial blood oxygen saturation from the central source site with an estimate, taken at a similar time, of the arterial blood oxygen saturation from the first peripheral site; and

6. based on developed parameters, determine the presence or absence of, or the time-based changes in, impaired peripheral perfusion proximal to said first peripheral site based on the extent to which said first peripheral site has lower oxygen saturation than said central source site; and

d. a read-out device to provide results to a user of said system.

23. The oximeter monitor system of claim 22, additionally comprising software in said computer with steps for estimating blood pressure through analysis of pulse time delay between said at least two sites, including means for adjustment of blood pressure estimates based on at least one comparison with a result from a conventional blood pressure measurement of said living vertebrate.